Bridging Worldsheet CFTs and Wormholes

TL;DR

This paper explores worldsheet conformal field theories that describe stringy wormholes connecting disjoint spaces, extending beyond supergravity by including strongly coupled CFTs with throats at the string scale.

Contribution

It provides multiple examples of CFTs on the worldsheet that model string propagation through wormholes, including novel interpretations of conformal manifolds mediating universe-wormhole transitions.

Findings

Stringy wormholes described by strongly coupled CFTs.

Examples include Euclidean wormholes, double cones, and Einstein-Rosen bridges.

Conformal manifolds can mediate transitions between a closed universe and a wormhole.

Abstract

I provide multiple examples of conformal field theories (CFTs) on the worldsheet that describe string propagation in target space wormholes connecting two disjoint asymptotic manifolds. The worldsheet approach goes beyond the framework of supergravity by incorporating wormholes for which the size of the throat is comparable to the string scale. Typically, strongly coupled CFTs describe these stringy wormholes, which include Euclidean wormholes, double cones, and Einstein-Rosen bridges. Finally, I interpret a conformal manifold that contains $\text{SU}(2)_k$ and $\big(\text{SU}(2)_k \times \text{U}(1)_{k'}\big)/\text{U}(1)$ CFTs as mediating a transition between a closed Universe and a wormhole.